1. Field of the Invention
This invention concerns thermal liners having good thermal insulation and breathability under non-emergency conditions but, when under high thermal exposure, the liners provide an increase in thermal insulation and flame resistance thereby enhancing protection. The invention also covers a composite fabric system incorporating an outer shell fabric, a liquid barrier and the thermal liner. The invention further covers a protective garment.
2. Background of the Invention
The thermal liners or barriers used in firefighter's turnout coats have two thermal property needs that are in opposition to each other. During non-emergency conditions, the thermal liner should have good thermal insulation and breathability to provide maximum comfort for the wearer. However, in the event of a high thermal exposure such as encountered in an emergency condition, the thermal liner must have high thermal insulation in order to protect the wearer from burns. Turnout coats that provide high levels of thermal insulation are typically bulky during all conditions. The bulk of these coats inhibits the ability of the user to perform effectively due to movement inhibition and fatigue related to the garment weight. Thus, there is a need to provide adequate protection with reduced coat bulk during non-emergency conditions.
U.S. Pat. No. 7,229,937 to Bascom at al describes a non-woven fire blocking fabric comprising an open mesh scrim having crimped heat-resistant organic fibers compressed thereon and held in a compressed state by a thermoplastic binder. U.S. Pat. No. 7,247,585 also to Bascom at al describes a modification of the concept patented above wherein then fire-blocking fabric has ridges and grooves. U.S. Pat. No. 7,226,877 to Bascom et al teaches an impermeable polymeric film laminated to an open mesh scrim having crimped heat-resistant organic fibers compressed thereon and held in a compressed state by a thermoplastic binder. U.S. Pat. No. 6,955,193 to Hainsworth et al discloses a fire resistant woven fabric material comprising a front face woven from meta-aramid fiber and a back face woven from para-aramid fiber.
Despite the functionality of these fabrics, there is still a need for further improvements particularly in the areas of flame resistance of the finished garment, minimizing shrinkage reduction of the thermal liner and reducing abrasion resistance of the thermal liner.